How to suppress output

Question

I would like to suppress output in R when I run my R script from the command prompt.

I tried numerous options including --slave and --vanilla. Those options lessens the amount of text outputted.

I also tried to pipe the output to NUL but that didn't help.

Forman

Maybe R is printing to stderr if > NUL doesn't help. Try appending 2>&1 as well. – Nealah

Answer 1

Look at help(sink) to do that. On Unix I'd do

sink("/dev/null")    # now suppresses
....                 # do stuff
sink()               # to undo prior suppression, back to normal now

and the Windows equivalent (with a tip-of-the-hat to Johannes) is

sink("NUL")
....
sink()

Electroballistics

Usually the Windows equivalent is NUL. However, it may well be that CreateFile, &c. won't be able to open it and that it's largely special functionality in the shell which enables its workings. – Nealah

Thank you -- I edited the answer accordingly (after testing that it does indeed work that way with NUL quoted properly). – Electroballistics

Hi @DirkEddelbuettel, I noted that this doesn't for dumping errors from try() sections, sink(file="NUL", type="message") complains that "NUL" isn't a file connection, in those cases one needs to use the try(stop("error msg"), silent=TRUE) for it to work as expected. Just wanted to add this to your answer in case anyone else stumbles upon this answer. – Fibrovascular

So, is there a universal (platform independent) way to achieve this other than simply supplying a tempfile()? – Incognizant

Answer 2

Since R (>= 3.6.0), there exists a platform-independent alternative to Dirk Eddelbuettel's answer. Simply type

sink(nullfile())    # suppress output
....                # your code
sink()              # end suppressing output

to suppress output on both Linux and Windows.

Ruberta

If including this in a function, then can wrap inside on.exit(sink()) - otherwise unexpected errors in the function may leave you wondering why you have no output to the console. – Partisan